266 DOC. 22 SOLVAY
DISCUSSION REMARKS
to
try
to set
up
an
energy
balance. In the
case
where
only
1
ß-particle
each and
(monochromatic)
y-rays
are
generated,
one
would have
to
expect,
for
example,
the
following.
If
E1
E2
... En ...
are
the kinetic
energies
of
ß-rays
of
different
velocities and
v1
...
vn
...
the
frequencies
of the
y-rays,
then it would have
to
be
possible
to
correlate the
different
ß-
and
y-rays
with
one
another in such
a
way
that
(En
+
hvn
=
energy
of
radioactive
transformation)
is,
thus,
the
same
for all values of
n.
IV. Grüneisen
Eduard Grüneisen's lecture
(Grüneisen 1921)
dealt with the molecular
theory
of solids. In
a
discussion
remark headed
"Thermodynamic
Discussion"
("Discussion Thermodynamique"),
Walther Nernst returned
to
the dicussion
following
his lecture
at
the first
Solvay Congress.
In that discussion Einstein had
expressed
his doubts about Nernst's claim that his heat
theorem could be derived from the
vanishing
of the
specific
heats
as
the
temperature
goes
to
zero
(see
Vol.
3,
Doc.
25,
pp.
513-514;
see
also Vol.
5,
Doc.
364, note
6,
for
a
review of this
controversy
between Einstein and Nernst
on
the heat
theorem).
Nernst
now
claimed
that
a new
derivation
(see
Nernst
1912)
as
well
as new
experimental
data had refuted Einstein's
objections.
Einstein's first remark
is
a
response to
the
following argument by
Nernst: the heat theorem
predicts
that
dp/dT
vanishes
at
low
temperatures. Suppose
that
dp/dT
remains
finite. Then it would be
possible to
reach
absolute
zero
through
a
finite
expansion process,
and
one
could
perform a thermodynamic cycle
that
violates Carnot's
principle.
Nernst's conclusion
is
that
dp/dT equals zero
for
zero temperature,
from which
one can
conclude that
his theorem
is
valid. Einstein's second remark follows
a
comment
by
H.
A.
Lorentz,
who outlined his
own
proof of
Nernst's theorem. Lorentz concludes his intervention with the
statement
that
in his view Nernst's
new proof
is correct.
Transcribed from PSSC,
p.
329
(Grüneisen
et
al.
1921,
p.
291)
I
concede this
completely.
Transcribed from
PSSC,
pp.
331-337
(Grüneisen
et al.
1921,
pp.
293-298)
The
question
we
must treat
here before all
else is
as
follows. Since the
experimental
investigations
of Nernst and his students have
convincingly
demonstrated
that,
at
low
temperatures,
the
heat
capacity
C of condensed
systems
tends
to
the value
zero more
strongly
than the
temperature
T
itself,
the
question
arises whether Nernst's heat
theorem is
proved by
this fact. At the first
Solvay Congress,
the views
on
this
point
turned
out to
be divided.
Mr.
Nernst himself
was
of the
opinion
that his theorem
could be
proved thermodynamically
from the
degeneration
of the
specific
heat at low
temperatures;
subsequently
he
sought
to
substantiate his view
by
means
of
a
thermodynamic investigation,
which-even
though
it did
not
achieve this
goal,
in
my